Part 8

-Diabetes

-Alzheimers

-Myasthenia gravis

-Glaucoma

Diabetes Overview

Diabetes is a set of related diseases in which the body cannot regulate the amount of sugar (glucose) in the blood.

Glucose in the blood gives you energy—the kind you need when you walk briskly, run for a bus, ride your bike, take an aerobics class, and perform your day-to-day chores.

• Glucose in the blood is produced by the liver from the foods you eat.
• In a healthy person, the blood glucose level is regulated by several hormones, one of which is insulin. Insulin is produced by the pancreas, a small organ near the stomach that also secretes important enzymes that help in the digestion of food.
• Insulin allows glucose to move from the blood into liver, muscle, and fat cells, where it is used for fuel.
• People with diabetes either do not produce enough insulin (type 1 diabetes) or cannot use insulin properly (type 2 diabetes), or both.
• In diabetes, glucose in the blood cannot move into cells, and it stays in the blood. This not only harms the cells that need the glucose for fuel, but also harms certain organs and tissues exposed to the high glucose levels.

Type 1 diabetes: The body stops producing insulin or produces too little insulin to regulate blood glucose level.

• Type 1 diabetes comprises about 10% of total cases of diabetes in the United States.
• Type 1 diabetes is typically recognized in childhood or adolescence. It used to be known as juvenile-onset diabetes or insulin-dependent diabetes mellitus.
• Type 1 diabetes can occur in an older individual due to destruction of pancreas by alcohol, disease, or removal by surgery or progressive failure of pancreatic beta cells, which produce insulin.
• People with type 1 diabetes generally require daily insulin treatment to sustain life.

Type 2 diabetes: The pancreas secretes insulin, but the body is partially or completely unable to use the insulin. This is sometimes referred to as insulin resistance. The body tries to overcome this resistance by secreting more and more insulin. People with insulin resistance develop type 2 diabetes when they do not continue to secrete enough insulin to cope with the higher demands.

• At least 90% of patients with diabetes have type 2 diabetes.
• Type 2 diabetes is typically recognized in adulthood, usually after age 45 years. It used to be called adult-onset diabetes mellitus, or non–insulin-dependent diabetes mellitus. These names are no longer used because type 2 diabetes does occur in younger people, and some people with type 2 diabetes need to use insulin.
• Type 2 diabetes is usually controlled with diet, weight loss, exercise, and oral medications. More than half of all people with type 2 diabetes require insulin to control their blood sugar levels at some point in the course of their illness.

Gestational diabetes is a form of diabetes that occurs during the second half of pregnancy.

• Although gestational diabetes typically goes away after delivery, women who have gestational diabetes are more likely than other women to develop type 2 diabetes later in life.
• Women with gestational diabetes are more likely to have large babies.

Metabolic syndrome (syndrome X) is a set of abnormalities in which insulin-resistant diabetes (type 2) is almost always present and includes hypertension, hyperlipidemia (increased serum lipids, predominant elevation of LDL, decrease in HDL, and elevated triglycerides), central obesity, and abnormalities in blood clotting and inflammatory responses. A high rate of cardiovascular disease is associated with the metabolic syndrome.

Prediabetes is a common condition related to diabetes. In people with prediabetes, the blood sugar level is higher than normal but not high enough to be considered diabetes.

• Prediabetes increases your risk of getting type 2 diabetes and of having heart disease or a stroke.
• Prediabetes can be reversed without insulin or medication by losing a modest amount of weight and increasing your physical activity. This can prevent, or at least delay, onset of type 2 diabetes.
• An international expert committee of the American Diabetes Association recently redefined the criteria for prediabetes, lowering the blood sugar level cut-off point for prediabetes. Approximately 20% more adults are now believed to have this condition and may develop diabetes within 10 years if they do not exercise or maintain a healthy weight.

About 17 million Americans (6.2%) are believed to have diabetes. About one third of those do not know they have it.

• About 1 million new cases occur each year, and diabetes is the direct or indirect cause of at least 200,000 deaths each year.
• The incidence of diabetes is increasing rapidly. This increase is due to many factors, but the most significant are the increasing incidence of obesity and the prevalence of sedentary lifestyles.

Complications of diabetes

Both forms of diabetes ultimately lead to high blood sugar levels, a condition called hyperglycemia. Over a long period of time, hyperglycemia damages the retina of the eye, the kidneys, the nerves, and the blood vessels.

• Damage to the retina from diabetes (diabetic retinopathy) is a leading cause of blindness.
• Damage to the kidneys from diabetes (diabetic nephropathy) is a leading cause of kidney failure.
• Damage to the nerves from diabetes (diabetic neuropathy) is a leading cause of foot wounds and ulcers, which frequently lead to foot and leg amputations.
• Damage to the nerves in the autonomic nervous system can lead to paralysis of the stomach (gastroparesis), chronic diarrhea, and an inability to control heart rate and blood pressure with posture changes.
• Diabetes accelerates atherosclerosis, or the formation of fatty plaques inside the arteries, which can lead to blockages or a clot (thrombus), which can then lead to heart attack, stroke, and decreased circulation in the arms and legs (peripheral vascular disease).
• Diabetes predisposes people to high blood pressure and high cholesterol and triglyceride levels. These independently and together with hyperglycemia increase the risk of heart disease, kidney disease, and other blood vessel complications.

In the short run, diabetes can contribute to a number of acute (short-lived) medical problems.

• Many infections are associated with diabetes, and infections are frequently more dangerous in someone with diabetes because the body's normal ability to fight infections is impaired. To compound the problem, infections may worsen glucose control, which further delays recovery from infection.
• Hypoglycemia, or low blood sugar, occurs from time to time in most people with diabetes. It results from taking too much diabetes medication or insulin (sometimes called insulin reaction), missing a meal, doing more exercise than usual, drinking too much alcohol, or taking certain medications for other conditions. It is very important to recognize hypoglycemia and be prepared to treat it at all times. Headache, feeling dizzy, poor concentration, tremors of hands, and sweating are common symptoms of hypoglycemia. You can faint or have a seizure if blood sugar level gets too low.
• Diabetic ketoacidosis is a serious condition in which uncontrolled hyperglycemia (usually due to complete lack of insulin or a relative deficiency of insulin) over time creates a buildup in the blood of acidic waste products called ketones. High levels of ketones can be very harmful. This typically happens to people with type 1 diabetes who do not have good blood glucose control. Diabetic ketoacidosis can be precipitated by infection, stress, trauma, missing medications like insulin, or medical emergencies like stroke and heart attack.
• Hyperosmolar hyperglycemic nonketotic syndrome is a serious condition in which the blood sugar level gets very high. The body tries to get rid of the excess blood sugar by eliminating it in the urine. This increases the amount of urine significantly and often leads to dehydration so severe that it can cause seizures, coma, even death. This syndrome typically occurs in people with type 2 diabetes who are not controlling their blood sugar levels or have become dehydrated or have stress, injury, stroke, or medications like steroids.

Diabetes Causes

Type 1 diabetes is believed to be an autoimmune disease. The body's immune system attacks the cells in the pancreas that produce insulin.

• A predisposition to develop type 1 diabetes may run in families but much less so than for type 2.
• Environmental factors, such as certain types of viral infections, may also contribute.
• Type 1 diabetes is most common in people of non-Hispanic white persons of Northern European descent, followed by African Americans and Hispanic Americans. It is relatively rare in those of Asian descent.
• Type 1 diabetes is slightly more common in men than in women.

Type 2 diabetes: Type 2 diabetes is believed to have a strong genetic link, meaning that it tends to run in families. Several genes are being studied that may be related to the cause of type 2 diabetes. Risk factors for developing type 2 diabetes include the following:

• High blood pressure
• High blood triglyceride (fat) levels
• Gestational diabetes or giving birth to a baby weighing more than 9 pounds
• High-fat diet
• High alcohol intake
• Sedentary lifestyle
• Obesity or being overweight
• Ethnicity: Certain groups, such as African Americans, Native Americans, Hispanic Americans, and Japanese Americans, have a greater risk of developing type 2 diabetes than non-Hispanic whites.
• Aging: Increasing age is a significant risk factor for type 2 diabetes. Risk begins to rise significantly at about age 45 years, and rises considerably after age 65 years.

Diabetes Symptoms

Symptoms of type 1 diabetes are often dramatic and come on very suddenly.

• Type 1 diabetes is usually recognized in childhood or early adolescence, often in association with an illness (such as a virus) or injury.
• The extra stress can cause diabetic ketoacidosis.
• Symptoms of ketoacidosis include nausea and vomiting. Dehydration and often-serious disturbances in blood levels of potassium follow.
• Without treatment, ketoacidosis can lead to coma and death.

Symptoms of type 2 diabetes are often subtle and may be attributed to aging or obesity.

• A person may have type 2 diabetes for many years without knowing it.
• People with type 2 diabetes can develop hyperglycemic hyperosmolar nonketotic syndrome.
• Type 2 diabetes can be precipitated by steroids and stress.
• If not properly treated, type 2 diabetes can lead to complications like blindness, kidney failure, heart disease, and nerve damage.

Common symptoms of both major types of diabetes

• Fatigue: In diabetes, the body is inefficient and sometimes unable to use glucose for fuel. The body switches over to metabolizing fat, partially or completely, as a fuel source. This process requires the body to use more energy. The end result is feeling fatigued or constantly tired.
• Unexplained weight loss: People with diabetes are unable to process many of the calories in the foods they eat. Thus, they may lose weight even though they eat an apparently appropriate or even excessive amount of food. Losing sugar and water in the urine and the accompanying dehydration also contributes to weight loss.
• Excessive thirst (polydipsia): A person with diabetes develops high blood sugar levels. The body tries to counteract this by sending a signal to the brain to dilute the blood, which translates into thirst. The body encourages more water consumption to dilute the high blood sugar back to normal levels and to compensate for the water lost by excessive urination.
• Excessive urination (polyuria): Another way the body tries to get rid of the extra sugar in the blood is to excrete it in the urine. This can also lead to dehydration because excreting the sugar carries a large amount of water out of the body along with it.
• Excessive eating (polyphagia): If the body is able, it will secrete more insulin in order to try to deal with the excessive blood sugar levels. Also the body is resistant to the action of insulin in type 2 diabetes. One of the functions of insulin is to stimulate hunger. Therefore, higher insulin levels lead to increased hunger and eating. Despite increased caloric intake, the person may gain very little weight and may even lose weight.
• Poor wound healing: High blood sugar levels prevent white blood cells, which are important in defending the body against bacteria and also in cleaning up dead tissue and cells, from functioning normally. When these cells do not function properly, wounds take much longer to heal and become infected more frequently. Also, long-standing diabetes is associated with thickening of blood vessels, which prevents good circulation and our body tissues from getting enough oxygen and other nutrients.
• Infections: Certain infection syndromes, such as frequent yeast infections of the genitals, skin infections, and frequent urinary tract infections, may result from suppression of the immune system by diabetes and by the presence of glucose in the tissues, which allows bacteria to grow well. They can also be an indicator of poor blood sugar control in a person known to have diabetes.
• Altered mental status: Agitation, unexplained irritability, inattention, extreme lethargy, or confusion can all be signs of very high blood sugar, ketoacidosis, or hyperosmolar hyperglycemia nonketotic syndrome or hypoglycemia (low sugar). Thus, any of these merit the immediate attention of a medical professional. Call your health care provider or 911.
• Blurry vision: Blurry vision is not specific for diabetes but is frequently present with high blood sugar levels.

Medical Treatment

The treatment of diabetes is highly individualized, depending on the type of diabetes, whether you have other active medical problems, whether you have complications of diabetes, and your age and general health at time of diagnosis.

• Your health care provider will set goals for lifestyle changes, blood sugar control, and treatment.
• Together, you will devise a plan to help you meet those goals.

Education about diabetes and its treatment is essential in all types of diabetes.

• When you are first diagnosed with diabetes, your diabetes care team will spend a lot of time with you, teaching you about your condition, your treatment, and everything you need to know to care for yourself on a daily basis.
• Your diabetes care team includes your health care provider and his or her staff. It may include specialists in foot care, neurology, kidney diseases, and eye diseases. A professional dietitian and a diabetes educator also may be part of the team.

Your care team will see you at appropriate intervals to monitor your progress with your goals.

Type 1 diabetes

Treatment of diabetes almost always involves the daily injection of insulin, usually a combination of short-acting insulin such as regular or Lispro or Aspart insulin and a longer acting insulin such as NPH, lente, glargine, detemir, or ultralente insulins.

• Insulin must be given as an injection. If taken by mouth, insulin would be destroyed in the stomach before it could get into the blood where it is needed.
• Most people with type 1 diabetes give these injections to themselves. Even if someone else usually gives you your injections, it is important that you know how to do it in case the other person is not available.
• A trained professional will show you how to store and inject the insulin. Usually this is a nurse who works with the health care provider or a diabetes educator.
• Insulin is usually given in 2 or 3 injections per day, generally around mealtimes. Dosage is individual and is tailored by the health care provider. Longer acting insulins are typically administered 1 or 2 times per day.
• Some people have their insulin administered by continuous infusion pumps to provide adequate blood glucose control. Supplemental mealtime insulin is programed into the pump by the individual as recommended by his or her health care provider.
• It is very important to eat if you have taken insulin, as the insulin will lower your blood sugar regardless of whether you have eaten. If you take insulin without eating, you could have hypoglycemia. This is called an insulin reaction.
• There is an adjustment period while you learn how insulin affects you and how to time your mealtimes and exercise times with your insulin injections to keep your blood sugar level as even as possible.
• Keeping accurate records of your blood sugar levels and insulin dosages is crucial in helping your health care provider take care of your diabetes.
• Eating a consistent, healthy diet appropriate for your size and weight is essential in controlling your blood sugar level.

Type 2 diabetes

Depending on how elevated your blood sugar and glycosylated hemoglobin are at the time of your diagnosis, you may be given a chance to lower your blood sugar level without medication.

• The best way to do this is to lose weight if you are obese and begin an exercise program.
• This will generally be tried for 3-6 months, and then your blood sugar and glycosylated hemoglobin will be rechecked. If they remain high, you will be started on an oral medication, usually a sulfonylurea or biguanide (Metformin), to help control your blood sugar level.
• Even if you are on medication, it is still important to eat a healthy diet, lose weight if you are overweight, and engage in moderate physical activity as often as possible.
• Your health care provider will monitor your progress on medication very carefully at first. It is important to get just the right dose of the right medication to get your blood sugar level in the recommended range with the fewest side effects.
• Your doctor may decide to combine two types of medications to get your blood sugar level under control.
• Gradually, even people with type 2 diabetes may require insulin injections to control their blood sugar levels.
• It is becoming more common for people with type 2 diabetes to take a combination of oral medication and insulin injections to control blood sugar levels.

Medications

Many different types of medications are available to help lower blood sugar levels in type 2 diabetes. Each type works in a different way. It is very common to combine 2 or more types to get the best effect with fewest side effects.

• Sulfonylureas: These drugs stimulate your pancreas to make more insulin.
• Sulfonylurea drugs. These medications stimulate your pancreas to produce and release more insulin. For them to be effective, your pancreas must produce some insulin on its own. Second-generation sulfonylureas such as glipizide (Glucotrol, Glucotrol XL), glyburide (DiaBeta, Glynase PresTab, Micronase) and glimepiride (Amaryl) are prescribed most often. The most common side effect of sulfonylureas is low blood sugar, especially during the first four months of therapy. You're at much greater risk of low blood sugar if you have impaired liver or kidney function

·         Biguanides: Metformin (Glucophage, Glucophage XR) is the only drug in this class available in the United States. It works by inhibiting the production and release of glucose from your liver, which means you need less insulin to transport blood sugar into your cells. One advantage of metformin is that is tends to cause less weight gain than do other diabetes medications. Possible side effects include a metallic taste in your mouth, loss of appetite, nausea or vomiting, abdominal bloating, or pain, gas and diarrhea. These effects usually decrease over time and are less likely to occur if you take the medication with food. A rare but serious side effect is lactic acidosis, which results when lactic acid builds up in your body. Symptoms include tiredness, weakness, muscle aches, dizziness and drowsiness. Lactic acidosis is especially likely to occur if you mix this medication with alcohol or have impaired kidney function

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• Alpha-glucosidase inhibitors: These agents slow absorption of the starches you eat. This slows down glucose production. Drugs in this class include acarbose (Precose) and miglitol (Glyset). Although safe and effective, alpha-glucosidase inhibitors can cause abdominal bloating, gas and diarrhea. If taken in high doses, they may also cause reversible liver damage.
• Thiazolidinediones: These agents increase your sensitivity to insulin. Side effects of thiazolidinediones, such as rosiglitazone (Avandia) and pioglitazone hydrochloride (Actos), include swelling, weight gain and fatigue. A far more serious potential side effect is liver damage. The thiazolidinedione troglitzeone (Rezulin) was taken off the market in March 2000 because it caused liver failure. If your doctor prescribes these drugs, it's important to have yourliver.
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·         Meglitinides:. These medications, such as repaglinide (Prandin), have effects similar to sulfonylureas, but you're not as likely to develop low blood sugar. Meglitinides work quickly, and the results fade rapidly.

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• D-phenylalanine derivatives: These agents stimulate your pancreas to produce more insulin more quickly.
• Amylin synthetic derivatives: Amylin is a naturally occurring hormone secreted by the pancreas along with insulin. An amylin derivative, such as <FONT color=